CIRCULAR DICHROISM SPECTROSCOPY IS BEING USED TO PROBE SECONDARY STRUCTURE CHANGES IN 3 DIFFERENT SYSTEMS AS FOLLOWS: 1. UNFOLDING sidvaut dissouation of glutatihione reductase induced by chaptronic agents . 2. conformational changes accompanying phospholipid removal from lipepherin and insect lipoprotein 3. pressure - induced conformational changes and unfolding of pyruvate kinase.